Chemistry Exam Past Questions and Answers | JAMB, WAEC and NECO

Chemistry is the study of the substances that make up matter. It looks at their properties, how they react with each other, and how these reactions can create new substances.

• Question 2171:

  Which of the following compounds is an example of an electrovalent bond?

  Options:
  A) NaCl (sodium chloride)
  B) CO2 (carbon dioxide)
  C) H2O (water)
  D) CH4 (methane)
  Show Answer
  The correct answer is A .
• Question 2172: The pollutants that are likely to be present in an industrial environment are? Options:
  A) H₂S,SO₂ and oxides of nitrogen
  B) NH₃, HCI and CO
  C) CO₂, NH₃ and H₂S
  D) dust, NO and CI₂
  Show Answer
  The correct answer is A .
• Question 2173: Synthetic rubber obtained by the polymerization of chlorobutadiene in the presence of sodium is called? Options:
  A) teflon
  B) isoprene
  C) polythene
  D) neoprene
  Show Answer
  The correct answer is D .
• Question 2174: The alkyl group is represented by the general formula Options:
  A) C_nH₂n
  B) C_nH₂n − 2
  C) C_nH₂n + 1
  D) C_nH₂n + 2
  Show Answer
  The correct answer is C .
• Question 2175: The hydroxyl ion concentrated, (OH^-), in a solution of sodium hydroxide of pH 10.0 is? Options:
  A) 10^-10 mol dm^-3
  B) 10^-6 mol dm^-3
  C) 10^-4 mol dm^-3
  D) 10^-2 mol dm^-3
  Show Answer
  The correct answer is C .
• Question 2176: Ethene when passed into concentrated H₂SO₄ is rapidly absorbed. The product is diluted with water and then warmed to produce? Options:
  A) ethanol
  B) diethyl ether
  C) ethanal
  D) diethyl sulphate
  Show Answer
  The correct answer is A .
• Question 2177: An organic compound contains 60% carbon, 13.3% hydrogen and 26.7% oxygen. Calculate the empirical formula
  rn(C=12,H =1, O=16) Options:
  A) C ₅H ₁₂O
  B) C ₃H ₈O
  C) C ₆H ₁₃O ₂
  D) C ₄H ₉O
  Show Answer
  The correct answer is B .
• Question 2178: Oxidation of concentrated hydrochloric acid with manganese (IV) oxide liberates a gas used in the? Options:
  A) manufacture of tooth pastes
  B) treatment of simple golitre
  C) vulcanization of rubber
  D) sterilization of water
  Show Answer
  The correct answer is D .
• Question 2179: Calculate the amount in moles of a gas which occupies 10.5 dm³ at 6 atm and 30^oC [R = 082 atm dm³ K^-1 mol^-1] Options:
  A) 2.536
  B) 1.623
  C) 4.736
  D) 0.394
  Show Answer
  The correct answer is A .
• Question 2180: Which of the following reactions takes place in the cathode compartment during the electrolysis of copper (II) chloride solution? Options:
  A) Cu²⁺ + 2e^- → Cu(s)
  B) 2Cl^- -2e → Cl₂
  C) Cu_(s) -2e → Cu²⁺_(aq)
  D) Cu²⁺_(aq) + 2Cl^-_(aq) → CuCl_2(aq)
  Show Answer
  The correct answer is A .